The ultrafast all-optical solid-state framing camera(UASFC) technique is a new diagnostic method based on the semiconductor photorefractive effect. The ultra-fast response characteristics of this method are mainly determined by the response time of the semiconductor material's photorefractive index change. How to quickly and accurately measure the photorefractive index response time of semiconductor materials is an important step in the development of all-optical solid ultra-fast diagnostic chip. In this paper, the 100fs pulsed laser is divided into two beams. One of which is used as excitation light to generate pulsed X-ray source; the other beam is measured as a spectral probe light. Through the test of GaAs material, the response time of the refractive index change of GaAs material was less than 5ps, which laid a foundation for further optimization experiment and accurate measurement.